Dynamic logical page sizes for memory devices

ABSTRACT

Methods, systems, and devices for dynamic logical page sizes for memory devices are described. A memory device may use an initial set of logical pages each having a same size and one or more logical-to-physical (L2P) tables to map logical addresses of the logical pages to the physical addresses of corresponding physical pages. As commands are received from a host device, the memory device may dynamically split a logical page to introduce smaller logic pages if the host device accesses data in chunk sizes smaller than the size of the logical page that is split. The memory device may maintain one or more additional L2P tables for each smaller logical page size that is introduced, along with one or more pointer tables to map between L2P tables and entries for larger logical page sizes and L2P tables and entries associated with smaller logical page sizes.

CROSS REFERENCE

The present Application for Patent is a continuation of U.S. patentapplication Ser. No. 17/117,907 by Ambula et al., entitled “DYNAMICLOGICAL PAGE SIZES FOR MEMORY DEVICES,” filed Dec. 10, 2020, assigned tothe assignee hereof, and is expressly incorporated by reference in itsentirety herein.

FIELD OF TECHNOLOGY

The following relates generally to one or more systems for memory andmore specifically to dynamic logical page sizes for memory devices.

BACKGROUND

Memory devices are widely used to store information in variouselectronic devices such as computers, wireless communication devices,cameras, digital displays, and the like. Information is stored byprograming memory cells within a memory device to various states. Forexample, binary memory cells may be programmed to one of two supportedstates, often corresponding to a logic 1 or a logic 0. In some examples,a single memory cell may support more than two possible states, any oneof which may be stored by the memory cell. To access information storedby a memory device, a component may read, or sense, the state of one ormore memory cells within the memory device. To store information, acomponent may write, or program, one or more memory cells within thememory device to corresponding states.

Various types of memory devices exist, including magnetic hard disks,random access memory (RAM), read-only memory (ROM), dynamic RAM (DRAM),synchronous dynamic RAM (SDRAM), ferroelectric RAM (FeRAM), magnetic RAM(MRAM), resistive RAM (RRAM), flash memory, phase change memory (PCM),3-dimensional cross-point memory (3D cross point), not-or (NOR), andnot-and (NAND) memory devices, and others. Memory devices may bevolatile or non-volatile. Volatile memory cells (e.g., DRAM cells) maylose their programmed states over time unless they are periodicallyrefreshed by an external power source. Non-volatile memory cells (e.g.,NAND memory cells) may maintain their programmed states for extendedperiods of time even in the absence of an external power source.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a system that supports dynamic logicalpage sizes for memory devices in accordance with examples as disclosedherein.

FIG. 2 illustrates an example of an L2P table architecture that supportsdynamic logical page sizes for memory devices in accordance withexamples as disclosed herein.

FIG. 3 illustrates an example of a process flow that supports dynamiclogical page sizes for memory devices in accordance with examples asdisclosed herein.

FIG. 4 illustrates an example of an operational flow supports dynamiclogical page sizes for memory devices in accordance with examples asdisclosed herein.

FIG. 5 illustrates an example of a process flow that supports dynamiclogical page sizes for memory devices in accordance with examples asdisclosed herein.

FIG. 6 shows a block diagram of a memory system that supports dynamiclogical page sizes for memory devices in accordance with aspects of thepresent disclosure.

FIGS. 7 and 8 show flowcharts illustrating a method or methods thatsupport dynamic logical page sizes for memory devices in accordance withexamples as disclosed herein.

DETAILED DESCRIPTION

Memory cells within a memory device may each be associated with acorresponding physical address, where a physical address may identifythe physical location of a corresponding memory cell within the memorydevice. The physical location of data within a memory device may changeover time, due to the memory device accommodating the writing ofadditional data, maintenance operations performed by the memory device,or for any number of other reasons. A host device for the memory devicemay reference data (e.g., when issuing read, write, or other commandsassociated with the data) using logical addresses (which mayalternatively be referred to as virtual addresses or system addresses,among other possibilities), and the memory device may maintain a mappingbetween the logical addresses associated with data stored by the memorydevice and the physical addresses of the memory cells at which the datais stored, which may support the memory device changing the physicaladdresses over time as described herein.

For example, the host device may refer to the location of data stored inthe memory device using a logical block address (LBA), which may bemapped to a physical address of a page of memory of the memory device atwhich the data is stored, where a page may refer to a grouping of memorycells as explained further herein. Though examples may be describedherein with reference to LBAs, it is to be understood that the teachingsherein may be extended to other types of logical addresses. Because thephysical address of the data may change, some memory devices maymaintain one or more logical-to-physical (L2P) tables that map LBAsreferenced by the host device to corresponding physical addresses ofpages in the memory device. In this manner, the host device can requestto read data from the memory device using the same LBA as was used forwriting the data even if the data was moved to a different physicaladdress during the interim.

Some memory devices partition physical pages into logical pages thathave a different page size than the physical page size. For example, amemory device may have a physical page size of 16 KB, and these physicalpages may be partitioned into logical pages that each have a logicalpage size of 4 KB. In this case, the L2P tables may be used to map LBAsprovided by the host to physical addresses of logical pages, therebyenabling the host device to read and write data to a smaller page sizethan the physical page size. Such L2P tables may require more entriesthan L2P tables that map LBAs to physical addresses, however, becausethere are more logical pages than physical pages.

The length of an L2P table (in terms of the quantity of entries) mayaffect the performance of the memory device. For example, the memorydevice may incur more overhead for generating, storing, maintaining, andtraversing longer L2P tables than for shorter L2P tables. Thus, reducingthe quantity of entries in an L2P table may lead to performanceimprovements. Further, consulting L2P tables may incur latency inresponding to a command (e.g., read or write command) issued by the hostdevice. For example, L2P tables may be stored within the memory deviceand read by a controller for (e.g., coupled with) the memory device, andin some cases L2P tables may be organized as a hierarchy of L2P tables.Thus, aspects of the teaching herein, including reducing a number oftables that may be traversed or read from the memory device in order toidentify the physical address corresponding to the data associated withan LBA, may further provide latency benefits, among other benefits thatmay be appreciated by one of ordinary skill in the art.

As described herein, a memory device may reduce the quantity of entriesin L2P tables by using multiple and dynamic logical page sizes, wherethe size of logical pages used by the memory device may be dynamic andmay range from a maximum logical page size (which may be the same as orlarger than the physical page size of the memory device) to a minimumlogical page size (which may be smaller than a physical page size of thememory device)—e.g., as opposed to using only a single logical pagesize, using only logical pages each having a fixed size, or both. Thememory device may select the logical page size for storing the dataassociated with a write command based on the size (e.g., quantity,length) of the data to be written, and may maintain multiple L2P tablesthat are each associated with a particular logical page size among themultiple logical page sizes that may be used by the memory device.

For example, the memory device may initially generate or otherwise storeL2P tables with entries that each point to logical pages having themaximum page size, thereby reducing the quantity of entries in these L2Ptables. If the host requests to write an amount of data that wouldconsume the maximum page size, the memory device may use these L2Ptables to locate a logical page of the maximum page size for writing thedata. If, however, the host requests to write data that can beaccommodated by a smaller logical page size, the memory device may splitthe larger logical pages into a group of two or more smaller logicalpages and store the data in a smaller logical page within the prior,larger logical page.

To enable subsequent retrieval of the data from the smaller logicalpage, the memory device may update the original L2P entry pointing tothe larger logical page to indicate that the page has been split. Thememory device may create a new L2P table that includes entries pointingto the smaller logical pages, and may add or update an entry in an L2Ppointer table that points to the new L2P table and indicates the lengthof the new L2P table.

When the host device subsequently requests to read the data, the memorydevice may traverse the two levels of L2P tables to find the data basedon the LBA. For example, the memory device may read the entry in theoriginal L2P table corresponding to the requested LBA, determine thatthe larger logical page has been split, read an entry in the L2P pointertable to identify the location and length of the new L2P table, and readan entry in the new L2P table to find the location of the data.

As described herein, this approach enables the memory device to usefewer or shorter L2P tables when the host requests to read or writelarge data streams (such as for streaming audio or video) while allowingthe memory device to split the larger logical pages into smaller logicalpages when the host device requests to write smaller amounts of data.Thus, the size and assortment of logical page sizes and the size andquantity of L2P tables used by the memory device may dynamically changein response to commands issued by the host device, with the memorydevice initially using few and short L2P tables along with large logicalpages and, during operation, increasing the count and length of L2Ptables and introducing smaller logical page sizes on a dynamic (e.g.,“as-needed”) basis. These and other techniques described herein mayallow the memory device to use a quantity and length of L2P table andlogical addresses that is “right-sized” for the data access patterns ofthe host device, thereby providing latency, overhead, and other benefitsas described herein or as may otherwise be appreciated by one ofordinary skill in the art.

Features of the disclosure are initially described in the context of asystem as described with reference to FIG. 1 . Features of thedisclosure are described in the context operational flows and processflows as described with reference to FIGS. 2-5 . These and otherfeatures of the disclosure are further illustrated by and described withreference to an apparatus diagram and flowcharts that relate to dynamiclogical page sizes for memory devices as described with reference toFIGS. 6-8 .

FIG. 1 is an example of a system 100 that supports dynamic logical pagesizes for memory devices in accordance with examples as disclosedherein. The system 100 includes a host system 105 coupled with a memorysystem 110.

A memory system 110 may be or include any device or collection ofdevices, where the device or collection of devices includes at least onememory array. For example, a memory system 110 may be or include aUniversal Flash Storage (UFS) device, an embedded Multi-Media Controller(eMMC) device, a flash device, a universal serial bus (USB) flashdevice, a secure digital (SD) card, a solid-state drive (SSD), a harddisk drive (HDD), a dual in-line memory module (DIMM), a small outlineDIMM (SO-DIMM), or a non-volatile DIMM (NVDIMM), among otherpossibilities.

The system 100 may be included in a computing device such as a desktopcomputer, a laptop computer, a network server, a mobile device, avehicle (e.g., airplane, drone, train, automobile, or other conveyance),an Internet of Things (IoT) enabled device, an embedded computer (e.g.,one included in a vehicle, industrial equipment, or a networkedcommercial device), or any other computing device that includes memoryand a processing device.

The system 100 may include a host system 105, which may be coupled withthe memory system 110. In some examples, this coupling may include aninterface with a host system controller 106, which may be an example ofa control component configured to cause the host system 105 to performvarious operations in accordance with examples as described herein. Thehost system 105 may include one or more devices, and in some cases mayinclude a processor chipset and a software stack executed by theprocessor chipset. For example, the host system 105 may include anapplication configured for communicating with the memory system 110 or adevice therein. The processor chipset may include one or more cores, oneor more caches (e.g., memory local to or included in the host system105), a memory controller (e.g., NVDIMM controller), and a storageprotocol controller (e.g., PCIe controller, SATA controller). The hostsystem 105 may use the memory system 110, for example, to write data tothe memory system 110 and read data from the memory system 110. Althoughone memory system 110 is shown in FIG. 1 , it is to be understood thatthe host system 105 may be coupled with any quantity of memory systems110.

The host system 105 may be coupled with the memory system 110 via atleast one physical host interface. The host system 105 and the memorysystem 110 may in some cases be configured to communicate via a physicalhost interface using an associated protocol (e.g., to exchange orotherwise communicate control, address, data, and other signals betweenthe memory system 110 and the host system 105). Examples of a physicalhost interface may include, but are not limited to, a serial advancedtechnology attachment (SATA) interface, a UFS interface, an eMMCinterface, a peripheral component interconnect express (PCIe) interface,a USB interface, a Fiber Channel interface, a Small Computer SystemInterface (SCSI), a Serial Attached SCSI (SAS), a Double Data Rate (DDR)interface, a dual in-line memory module (DIMM) interface (e.g., DIMMsocket interface that supports DDR), an Open NAND Flash Interface(ONFI), and a Low Power Double Data Rate (LPDDR) interface. In someexamples, one or more such interfaces may be included in or otherwisesupported between a host system controller 106 of the host system 105and a memory system controller 115 of the memory system 110. In someexamples, the host system 105 may be coupled with the memory system 110(e.g., the host system controller 106 may be coupled with the memorysystem controller 115) via a respective physical host interface for eachmemory device 130 included in the memory system 110, or via a respectivephysical host interface for each type of memory device 130 included inthe memory system 110.

Memory system 110 may include a memory system controller 115 and one ormore memory devices 130. A memory device 130 may include one or morememory arrays of a any type of memory cells (e.g., non-volatile memorycells, volatile memory cells, or any combination thereof). Although twomemory devices 130-a and 130-b are shown in the example of FIG. 1 , itis to be understood that memory system 110 may include any quantity ofmemory devices 130. Further, where memory system 110 includes more thanone memory device 130, different memory devices 130 within memory system110 may include the same or different types of memory cells.

The memory system controller 115 may be coupled with and communicatewith the host system 105 (e.g., via the physical host interface), andmay be an example of a control component configured to cause the memorysystem 110 to perform various operations in accordance with examples asdescribed herein. The memory system controller 115 may also be coupledwith and communicate with memory devices 130 to perform operations suchas reading data, writing data, erasing data, or refreshing data at amemory device 130, and other such operations, which may generically bereferred to as access operations. In some cases, the memory systemcontroller 115 may receive commands from the host system 105 andcommunicate with one or more memory devices 130 to execute such commands(e.g., at memory arrays within the one or more memory devices 130). Forexample, the memory system controller 115 may receive commands oroperations from the host system 105 and may convert the commands oroperations into instructions or appropriate commands to achieve thedesired access of the memory devices 130. And in some cases, the memorysystem controller 115 may exchange data with the host system 105 andwith one or more memory devices 130 (e.g., in response to or otherwisein association with commands from the host system 105). For example, thememory system controller 115 may convert responses (e.g., data packetsor other signals) associated with the memory devices 130 intocorresponding signals for the host system 105.

The memory system controller 115 may be configured for other operationsassociated with the memory devices 130. For example, the memory systemcontroller 115 may execute or manage operations such as wear-levelingoperations, garbage collection operations, error control operations suchas error-detecting operations or error-correcting operations, encryptionoperations, caching operations, media management operations, backgroundrefresh, health monitoring, and address translations between logicaladdresses (e.g., logical block addresses (LBAs)) associated withcommands from the host system 105 and physical addresses (e.g., physicalblock addresses) associated with memory cells within the memory devices130.

The memory system controller 115 may include hardware such as one ormore integrated circuits or discrete components, a buffer memory, or acombination thereof. The hardware may include circuitry with dedicated(e.g., hard-coded) logic to perform the operations ascribed herein tothe memory system controller 115. The memory system controller 115 maybe or include a microcontroller, special purpose logic circuitry (e.g.,a field programmable gate array (FPGA), an application specificintegrated circuit (ASIC), a digital signal processor (DSP)), or anyother suitable processor or processing circuitry.

The memory system controller 115 may also include a local memory 120. Insome cases, the local memory 120 may include read-only memory (ROM) orother memory that may store operating code (e.g., executableinstructions) executable by the memory system controller 115 to performfunctions ascribed herein to the memory system controller 115. In somecases, the local memory 120 may additionally or alternatively includestatic random access memory (SRAM) or other memory that may be used bythe memory system controller 115 for internal storage or calculations,for example, related to the functions ascribed herein to the memorysystem controller 115. Additionally or alternatively, the local memory120 may serve as a cache for the memory system controller 115. Forexample, data may be stored in the local memory 120 when read from orwritten to a memory device 130, and may be available within the localmemory 120 for subsequent retrieval for or manipulation (e.g., updating)by the host system 105 (e.g., with reduced latency relative to a memorydevice 130) in accordance with a cache policy.

Although the example of memory system 110 in FIG. 1 has been illustratedas including the memory system controller 115, in some cases, a memorysystem 110 may not include a memory system controller 115. For example,the memory system 110 may additionally or alternatively rely upon anexternal controller (e.g., implemented by the host system 105) or one ormore local controllers 135, which may be internal to memory devices 130,respectively, to perform the functions ascribed herein to the memorysystem controller 115. In general, one or more functions ascribed hereinto the memory system controller 115 may in some cases instead beperformed by the host system 105, a local controller 135, or anycombination thereof. In some cases, a memory device 130 that is managedat least in part by a memory system controller 115 may be referred to asa managed memory device. An example of a managed memory device is amanaged NAND (MNAND) device.

A memory device 130 may include one or more arrays of non-volatilememory cells. For example, a memory device 130 may include NAND (e.g.,NAND flash) memory, ROM, phase change memory (PCM), self-selectingmemory, other chalcogenide-based memories, ferroelectric RAM (FeRAM),magneto RAM (MRAM), NOR (e.g., NOR flash) memory, Spin Transfer Torque(STT)-MRAM, conductive bridging RAM (CBRAM), resistive random accessmemory (RRAM), oxide based RRAM (OxRAM), and electrically erasableprogrammable ROM (EEPROM). Additionally or alternatively, a memorydevice 130 may include one or more arrays of volatile memory cells. Forexample, a memory device 130 may include random access memory (RAM)memory cells, such as dynamic RAM (DRAM) memory cells and synchronousDRAM (SDRAM) memory cells.

In some examples, a memory device 130 may include (e.g., on a same dieor within a same package) a local controller 135, respectively, whichmay execute operations on one or more memory cells of the memory device130. A local controller 135 may operate in conjunction with a memorysystem controller 115 or may perform one or more functions ascribedherein to the memory system controller 115.

In some cases, a memory device 130 may be or include a NAND device(e.g., NAND flash device). A memory device 130 may be or include amemory die 160. For example, in some cases, a memory device 130 may be apackage that includes one or more dies 160. A die 160 may, in someexamples, be a piece of electronics-grade semiconductor cut from a wafer(e.g., a silicon die cut from a silicon wafer). Each die 160 may includeone or more planes 165, and each plane 165 may include a respective setof blocks 170, where each block 170 may include a respective set ofpages 175, and each page 175 may include a set of memory cells.

In some cases, a NAND memory device 130 may include memory cellsconfigured to each store one bit of information, which may be referredto as single level cells (SLCs). Additionally or alternatively, a NANDmemory device 130 may include memory cells configured to each storemultiple bits of information, which may be referred to as multi-levelcells (MLCs) if configured to each store two bits of information, astri-level cells (TLCs) if configured to each store three bits ofinformation, as quad-level cells (QLCs) if configured to each store fourbits of information, or more generically as multiple-level memory cells.Multiple-level memory cells may provide greater density of storagerelative to SLC memory cells but may, in some cases, involve narrowerread or write margins or greater complexities for supporting circuitry.

In some cases, planes 165 may refer to groups of blocks 170, and in somecases, concurrent operations may take place within different planes 165.For example, concurrent operations may be performed on memory cellswithin different blocks 170 so long as the different blocks 170 are indifferent planes 165. In some cases, performing concurrent operations indifferent planes 165 may be subject to one or more restrictions, such asidentical operations being performed on memory cells within differentpages 175 that have the same page address within their respective planes165 (e.g., related to command decoding, page address decoding circuitry,or other circuitry being shared across planes 165).

In some cases, a block 170 may include memory cells organized into rows(pages 175) and columns (e.g., strings, not shown). For example, memorycells in a same page 175 may share (e.g., be coupled with) a common wordline, and memory cells in a same string may share (e.g., be coupledwith) a common digit line (which may alternatively be referred to as abit line).

For some NAND architectures, memory cells may be read and programmed(e.g., written) at a first level of granularity (e.g., at the page levelof granularity) but may be erased at a second level of granularity(e.g., at the block level of granularity). That is, a page 175 may bethe smallest unit of memory (e.g., set of memory cells) that may beindependently programmed or read (e.g., programed or read concurrentlyas part of a single program or read operation), and a block 170 may bethe smallest unit of memory (e.g., set of memory cells) that may beindependently erased (e.g., erased concurrently as part of a singleerase operation). Further, in some cases, NAND memory cells may beerased before they can be re-written with new data. Thus, for example, aused page 175 may in some cases not be updated until the entire block170 that includes the page 175 has been erased.

In some cases, to update some data within a block 170 while retainingother data within the block 170, the memory device 130 may copy the datato be retained to a new block 170 and write the updated data to one ormore remaining pages of the new block 170. The memory device 130 (e.g.,the local controller 135) or the memory system controller 115 may markor otherwise designate the data that remains in the old block 170 asinvalid or obsolete, and update an L2P mapping table to associate thelogical address (e.g., LBA) for the data with the new, valid block 170rather than the old, invalid block 170. In some cases, such copying andremapping may be preferable to erasing and rewriting the entire oldblock 170, due to latency or wearout considerations, for example. Insome cases, one or more copies of an L2P mapping table may be storedwithin the memory cells of the memory device 130 (e.g., within or moreblocks 170 or planes 165) for use (e.g., reference and updating) by thelocal controller 135 or memory system controller 115.

In some cases, L2P tables may be maintained and data may be marked asvalid or invalid at the page level of granularity, and a page 175 maycontain valid data, invalid data, or no data. Invalid data may be datathat is outdated due to a more recent or updated version of the databeing stored in a different page 175 of the memory device 130. Invaliddata have been previously programmed to the invalid page 175 but may nolonger be associated with a valid logical address, such as a logicaladdress referenced by the host system 105. Valid data may be the mostrecent version of such data being stored on the memory device 130. Apage 175 that includes no data may be a page 175 that has never beenwritten to or that has been erased.

In some cases, a memory system controller 115 or a local controller 135may perform operations (e.g., as part of one or more media managementalgorithms) for a memory device 130, such as wear leveling, backgroundrefresh, garbage collection, scrub, block scans, health monitoring, orothers, or any combination thereof. For example, within a memory device130, a block 170 may have some pages 175 containing valid data and somepages 175 containing invalid data. To avoid waiting for all of the pages175 in the block 170 to have invalid data in order to erase and reusethe block 170, an algorithm referred to as “garbage collection” may beinvoked to allow the block 170 to be erased and released as a free blockfor subsequent write operations. Garbage collection may refer to a setof media management operations that include, for example, selecting ablock 170 that contains valid and invalid data, selecting pages 175 inthe block that contain valid data, copying the valid data from theselected pages 175 to new locations (e.g., free pages 175 in anotherblock 170), marking the data in the previously selected pages 175 asinvalid, and erasing the selected block 170. As a result, the number ofblocks 170 that have been erased may be increased such that more blocks170 are available to store subsequent data (e.g., data subsequentlyreceived from the host system 105).

The quantity and lengths of L2P tables (e.g., in terms of the quantityof entries) may affect the performance of the memory device. Forexample, the memory device may incur more overhead for generating,maintaining, and traversing longer L2P tables than for shorter L2Ptables. Thus, reducing the quantity, lengths, or both of L2P tables maylead to performance improvements.

The memory system 110 may reduce the quantity, lengths, or both of L2Ptables by using multiple, dynamic logical page sizes as describedherein. For example, a memory device 130 may initially generate L2Ptables with entries that point to logical pages having a maximum pagesize, thereby reducing the quantity of entries in the L2P tables of eachrespective memory device. The memory system controller 115 may initiallygenerate a main L2P table with entries that map LBAs to the initiallygenerated L2P tables of the memory device 130. If the host system 105requests to write an amount of data, for example to the memory device130, that would consume the maximum page size, the memory systemcontroller 115 may use the main L2P table and the L2P tables of thememory device 130 to locate a logical page of the maximum page size forwriting the data. If the host system 105 requests to write an amount ofdata that can be accommodated by a smaller logical page size, however,the memory device 130 may split the larger logical pages into a group oftwo or more smaller logical pages and store the data in a smallerlogical page within the larger logical page.

To enable subsequent retrieval of the data from the smaller logicalpage, the memory device 130 may update the original L2P entry pointingto the larger logical page to indicate that the page has been split. Thememory device 130 may create a new L2P table that includes entriespointing to the smaller logical pages, and the memory system controller115 may add or update an entry in an L2P pointer table stored in localmemory 120 that points to the new L2P table and indicates the length ofthe new L2P table.

When the host system 105 subsequently requests to read the data, thememory system controller 115 may traverse the two levels of L2P tablesto find the data based on the LBA. For example, the memory systemcontroller 115 may read the entry in the original L2P table of thememory device 130 corresponding to the requested LBA, determine that thelarger logical page has been split, read an entry in the L2P pointertable of the local memory 120 to identify the location and length of thenew L2P table, and read an entry in the new L2P table of the memorydevice 130 to find the location of the data.

As described herein, this approach enables the memory system 110 to useshorter L2P tables when the host system 105 requests to read or writelarge data streams (such as for streaming audio or video) while allowingthe memory device 130 to split the larger logical pages into smallerlogical pages when the host system 105 requests to write smaller amountsof data.

The system 100 may include any quantity of non-transitory computerreadable media that support dynamic logical page sizes for memorydevices. For example, the host system 105, the memory system controller115, or a memory device 130 may include or otherwise may access one ormore non-transitory computer readable media storing instructions (e.g.,firmware) for performing the functions ascribed herein to the hostsystem 105, memory system controller 115, or memory device 130. Forexample, such instructions, when executed by the host system 105 (e.g.,by the host system controller 106), by the memory system controller 115,or by a memory device 130 (e.g., by a local controller 135), may causethe host system 105, memory system controller 115, or memory device 130to perform one or more associated functions as described herein.

FIG. 2 illustrates an example of an L2P table architecture 200 thatsupports dynamic logical page sizes for memory devices in accordancewith examples as disclosed herein. In some examples, the L2P tablearchitecture 200 may be implemented by a memory system such as such asmemory system 110 described with reference to FIG. 1 . For example, theL2P table architecture 200 may be implemented by a controller 205 and amemory device 210, which may be examples of a memory system controller115 and a memory device 130 or 140 as described with reference to FIG. 1. In some examples, the L2P architecture 200 may be implemented inresponse one or more commands (e.g., one or more write commands, readcommands, or other commands).

The controller 205 may store and maintain one or more tables in a localmemory of the controller (e.g., a local memory 120 as described withreference to FIG. 1 ) that are used for mapping LBAs to correspondingL2P tables located in the memory device 210. For example, the controller205 may maintain a main L2P table 215. The main L2P table 215 mayinclude a quantity of entries 225 (e.g., 8 entries 225, or some otherquantity of entries 225) that each map an LBA to a corresponding L2Ptable 220 of the memory device 210. For example, an entry 225-a may mapan LBA to an L2P table 220-a. In some cases, an entry 225 may include aphysical address of a corresponding L2P table 220. For example, theentry 225-a may include a physical address of the L2P table 220-a. Insome cases, the entries 225 may be 4 byte (B) physical addresses.

The memory device 210 may include one or more tables that are used formapping LBAs to physical addresses of corresponding logical pages storedin the memory device 210. For example, the memory device 210 mayinitially generate a set of L2P tables 220 that each include a quantityof entries 230 (e.g., 128,000 entries 230, or some other quantity ofentries 230). An entry 230 may include a physical address of a logicalpage stored in the memory device 210. In some examples, each L2P table220 may be associated with a maximum logical page size x supported bythe memory device 210. For example, each entry 230 of an L2P table 220may include the physical address of a logical page of size x that isstored in the memory device 210. In some cases, the entries 230 may be4B physical addresses.

The memory device 210 may generate lower-level L2P tables associatedwith logical page sizes smaller than the maximum logical page size x.For example, if the host device requests to write an amount of data thatcan be accommodated by a logical page of a size smaller than x, thememory device 210 may split one or more logical pages of size x into agroup of two or more logical pages of the smaller size. The memorydevice 210 may create a new L2P table that includes the group of smallerlogical pages. For example, if the host device requests to write a sizeof data that may be closest to a size x/2, the memory device 210 maysplit a logical page of size x (e.g., the logical page pointed to byentry 230-a) into two logical pages each of size x/2. The memory device210 may generate an L2P table 245 associated with logical pages of sizex/2. For example, the memory device 210 may create the L2P table 245with two entries 250. A first entry 250 may include a physical addressof one of the two logical pages of size x/2, and a second entry 250 mayinclude a physical address of the other logical page of size x/2. Thememory device 210 may write the data to one or both of the logical pagesof size x/2 (e.g., if the size of data to be written is greater thanx/2). To enable subsequent retrieval of the data, the memory device 210may update at least a portion of the physical address of entry 230-a toindicate that the logical page pointed to by entry 230-a has been split.While the above example was described with respect to logical pages ofsize x/2, the memory device 210 may generate any number of additionallower-level L2P tables that are associated with a logical page sizesmaller than x and supported by the memory device 210. For example, thememory device 210 may generate an L2P table 255 with a quantity ofentries 260 that include physical addresses of logical pages of size x/4in response to receiving a write command from the host device.

The memory device 210 may maintain the lower-level L2P tables associatedwith logical page sizes smaller than the maximum logical page size x.For example, the memory device 210 may have previously generated one ormore lower-level L2P tables in response to receiving write commands fromthe host device. If the memory device 210 determines to split a logicalpage of size x to two or more logical pages of a smaller size and an L2Ptable associated with the smaller size already exists, the memory device210 may add entries to the existing L2P table that point to the newlogical pages rather than generate an additional L2P table associatedwith the smaller size. For example, if the L2P table 245 exists in thememory device 210 and the memory device determines to split a logicalpage of size x into two logical pages of size x/2, the memory device mayadd two entries 250 each associated with one of the two logical pages ofsize x/2 instead of generating an additional L2P table 245. In this way,the additional L2P tables may be associated with multiple logical pagesof size x that have been split.

The controller 205 may generate and maintain an L2P pointer table 235 inthe local memory of the controller. The controller 205 may use the L2Ppointer table 235 to track and locate the additional L2P tables storedin the memory device 210. For example, the L2P pointer table 240 mayinclude a quantity of entries 240 (e.g., 8 entries 240, or some otherquantity of entries 240) that each map a physical address from acorresponding entry 230 of an L2P table 220 to a physical address of acorresponding L2P table 245 of the memory device 210 that is associatedwith a logical page size smaller than the maximum logical page size x.In some examples, each entry 240 may be associated with a particular(e.g., respective) L2P table 245 and may track information related tothe particular L2P table 245. For example, an entry 240-a may beassociated with the L2P table 245. A first portion of the entry 240-amay include a physical address of the L2P table 245, and a secondportion of the entry 240-a may track the length of the L2P table 245.For example, when the memory device 210 generates the L2P table 245, thecontroller 205 may create the entry 240-a that includes the physicaladdress of the L2P table 245 in the first portion of the entry 240-a anda length (e.g., the quantity of entries 250) of the L2P table 245 in thesecond portion of the entry 240-a. If the L2P table 245 is subsequentlyupdated (e.g., entries 250 are added to or removed from the L2P table245), the controller may update the entry 240-a to specify the newlength of the L2P table 245. The controller may create and updateadditional entries 240 in response to the memory device 210 generatingand maintaining L2P tables associated with logical page sizes smallerthan the maximum logical page size x. In some cases, the entries 240 maybe 8B.

The controller 205 may store the main L2P table 215 and the L2P pointertable 235 in a first type of memory, and the memory device 210 may storeL2P tables (e.g., L2P tables 220, 245, and 250) in a second type ofmemory. In some cases, the first type of memory may be SRAM, and thesecond type of memory may be NAND memory. In some other cases, the firsttype of memory and the second type of memory may be the same type ofmemory.

In some examples, data previously written to a logical page may becomeinvalid or obsolete. The controller may mark or otherwise designate thedata of the other logical pages as invalid or obsolete (e.g., via anUNMAP command). As a result, the other logical pages may be free to bewritten with new data without losing the previously stored data.

The memory device may merge two or more free logical pages of alower-level L2P table. For example, if 4 128 KB logical pages are freedas a result of writing the data, the memory device may merge the 4 128KB logical pages into one 512 KB logical page. The memory device mayadjust a corresponding entry of the 512 KB L2P table to indicate thatthe logical page has not been split, and the controller may update acorresponding entry of the L2P pointer table with the new decreasedlength of an L2P table associated with the 128 KB logical pages.Additionally, the memory device may remove the entries of the L2P tablecorresponding to the 4 128 KB logical pages and shift any remainingentries of the L2P table up to occupy a gap created by the removal ofthe entries corresponding to the 4 128 KB logical pages. The memorydevice may update the offsets of any entries in corresponding 512 KB L2Ptables to indicate the new locations within the L2P table. In this way,the entries of the L2P table may remain continuous.

FIG. 3 illustrates an example of a process flow 300 that supportsdynamic logical page sizes for memory devices in accordance withexamples as disclosed herein. Process flow 300 may be performed bycomponents of a memory system, such as memory system 110 described withreference to FIG. 1 . For example, process flow 300 may be performed bya controller and a memory device such as memory system controller 115,controller 205, and memory device 130, 140, 210, as described withreference to FIGS. 1 and 2 , respectively. Process flow 300 may depict aprocess for generating and maintaining L2P tables (such as the L2Ptables depicted in FIG. 2 ) in response to receiving write commands froma host device. For clarity, process flow 300 uses the specific exampleof a memory device that has a 512 KB maximum logical page size, butsimilar processes apply to memory devices that have a different maximumlogical page size, which are also covered under the scope of thedisclosure.

At 305, the controller may receive a write command from a host device.The write command may include data to be written to the memory deviceand an LBA that the host device has assigned to the data and maysubsequently use to read the data.

In some examples, the controller may store virtual block informationassociated with the memory device and may assign a physical address ofthe data to be written based on the virtual block information. Forexample, the memory device may include one or more dies (e.g., dies 160)that each include one or more planes (e.g., planes 165). In some cases,a virtual block may be defined as a set of blocks of the same blocknumber from all of the planes of the memory device. For example, if thememory device include four dies and each of the dies includes fourplanes, then a virtual block 0 may be the set of blocks {die 0 plane 0block 0, die 0 plane 1 block 0, die 0 plane 2 block 0, , die 2 plane 0block 0, , die 3 plane 2 block 0, die 3 plane 3 block 0}. In some othercases, a virtual block may be defined as a subset of memory cells of ablock (e.g., a block 170) included in the memory device. The controllermay track which virtual blocks of the memory device are free, assign aphysical address to the data based on which virtual blocks are free, andwrite the data to the assigned physical address of the memory device.

In some examples, the controller may create a mapping between the LBAassigned to the data and the physical address of the data stored in thememory device and may store the mapping in a change log stored in thecontroller. The controller may subsequently use the mapping stored inthe change log to read the data. In some cases, the controller maydetermine to erase the mappings stored in the change log (e.g., due tochange log size restrictions, entering a low power mode). To avoidlosing the mappings, the controller may determine to store the mappingsin one or more L2P tables stored in the memory device. In some cases,310 to 380 may be implemented in response to the controller determiningto store the mappings in the one or more L2P tables. In some othercases, 310 to 380 may be implemented in response to receiving the writecommand from the host device at 305.

At 310, the controller may use the LBA as an index to read an entry in amain L2P table (e.g., entry 225-a in main L2P table 215) associated withthe LBA. The main L2P table may be stored in SRAM of the memory device,for example. The entry may include a physical address that points to a512 KB L2P table (e.g., L2P table 220-a).

At 315, the controller may determine (e.g., identify) an offsetassociated with the LBA to determine a particular entry of the 512 KBL2P table. For example, the physical address may point to the 512 KB L2Ptable and the controller may add the offset to this physical address todetermine a physical address of the particular entry in the 512 KB L2Ptable. As one example, the controller may determine the offset at 315based on a portion of bits included in the LBA—e.g., some quantity ofmost significant bits of the LBA may identify an entry 225 (e.g., entry225-a in main L2P table 215) associated with the LBA, and some otherquantity of bits (e.g., the remaining bits or some other portion of lesssignificant bits) may identify the offset determined at 315. Or asanother example, the entry 225 in main L2P table 215 may store anindication of the offset determined at 315.

The 512 KB L2P table may include entries that either (1) point directlyto a 512 KB logical page (if the 512 KB logical page has not been splitinto smaller logical pages), or (2) include an indication that the 512KB has been split into smaller logical page sizes, along with an offsetvalue that may subsequently be used to locate the data in the smallerlogical page. The 512 KB L2P table and corresponding 512 KB logicalpages may be stored in NAND memory of the memory device, for example.

At 320, the controller may read an entry in the 512 KB L2P table locatedat the physical address determined at 315. The entry may include aphysical address of a 512 KB logical page at which to write the datareceived from the host.

At 325, the controller may identify a logical page size based on thesize of the data that the host has requested to write in the writecommand. (Although process flow 300 depicts 325 as occurring after 320,in some examples, 325 may occur before 310, 315, or 320, or concurrentlywith 310, 315, or 320). The controller may identify the logical pagesize by selecting a logical page size from a set of logical page sizessupported by the memory device. For example, the memory device maysupport logical page sizes of 512 KB, 256 KB, 128 KB, 64 KB, 32 KB, 16KB, 8 KB, and 4 KB. The controller may select the logical page size thatis closest to the size of the data requested to be written by the host.The selected logical page size may be larger or smaller than the size ofthe data, and may be selected to optimize various aspects (e.g., tominimize a total quantity of logical pages, to minimize a quantity ofL2P table entries, or to optimize some other aspect). For example, ifthe host requests to write 400 KB of data, the controller may select alogical page size of 512 KB, and may write the data to a single 512 KBlogical page. If the host device requests to write 5 KB of data, thecontroller may select a logical page size of 4 KB, and may write thedata to two 4 KB logical pages. That is, the controller may write afirst portion of the data to a first 4 KB logical page and write asecond portion of the data to a second 4 KB logical page.

At 330, the controller may determine whether the selected logical pagesize is 512 KB (e.g., the maximum logical page size associated with thememory device).

If the selected logical page size is 512 KB, then at 335, the controllermay write the data to the 512 KB logical page that is pointed to by thephysical address read from the 512 KB L2P table at 320. In this case,the entry in the lower-level L2P table continues to point to the 512 KBlogical page at which the data is stored, and thus is not updated.

If the selected logical page size is not 512 KB, then at 340, thecontroller may determine whether there is already a pool of logicalpages that have the selected logical page sizes within the 512 KB pagepointed to by the second-level L2P table. For example, if the selectedlogical page size is 128 KB, the controller may determine whether the512 KB logical page pointed to has already been split into 128 KBlogical pages.

If the 512 KB page has not already been split into a pool of logicalpages having the selected logical page size, then the controller and/ormemory device may perform 345 through 360, as follows. In this case, thememory device may not yet have created a lower-level L2P table (e.g.,with respect to the 512KB L2P table) that points to logical pages withinthe pool, and therefore may create such an L2P table.

At 345, the memory device may split the 512 KB logical page into a poolof logical pages having the selected logical page size and write thedata to one or more logical pages within the pool. Further details ofsplitting the 512 KB logical page are described herein with reference toFIG. 4 below.

At 350, the memory device may create a new second-level L2P table (e.g.,L2P table 255) for the selected logical page size with an entry thatincludes the physical address of the data.

At 355, the controller may update an L2P pointer table (e.g., L2Ppointer table 235) by adding an entry to an L2P pointer table thatincludes (1) the physical address of the new lower-level L2P tableassociated with the selected logical page size and (2) the length of thelower-level L2P table in terms of the quantity of entries. In someexamples, the controller may create the L2P pointer table and add theentry to the L2P pointer table if no lower-level L2P tables werepreviously created or if all lower-level L2P tables were previouslyerased.

At 360, the memory device may update the entry in the 512 KB L2P tablethat was read at 320 to indicate that this 512 KB logical page has beensplit into smaller logical page sizes, and an offset that may be used tolocate the data within the smaller logical pages. For example, thememory device may store a value in the most-significant bit (MSB) thatindicates that the 512 KB logical page has been split, and threeadditional bits (e.g., bits 28, 29, 30 of a 4B entry) that may point toan entry of the L2P pointer table associated with the selected logicalpage size. In some examples, the offset may be stored in the remainingbits (e.g., bits 0 to 27 of a 4B entry) of the entry in the 512 KB L2Ptable.

If the 512 KB page has already been split into a pool of logical pageshaving the selected logical page size, then the controller and/or memorydevice may perform 365 through 375, as follows. In this case, the memorydevice may have already created a lower-level L2P table associated withthe selected logical page size.

At 365, the memory device may write the data to one or more logicalpages within the pool of logical pages.

At 370, the memory device may add or update an entry in thecorresponding lower-level L2P table with a physical address that pointsto the data. The length of the lower-level L2P table may therefore beincreased.

At 375, the memory device may update an entry in the L2P pointer tablethat points to the lower-level L2P table to reflect the new length ofthe lower-level L2P table.

At 380, the memory device may update the entry in the 512 KB L2P tablethat was read at 320 to indicate that this 512 KB logical page has beensplit into smaller logical page sizes, and an offset that may be used tolocate the data within the smaller logical pages. For example, thememory device may store a value in the MSB that indicates that the 512KB logical page has been split, and three additional bits (e.g., bits28, 29, 30 of a 4B entry) that may point to an entry of the L2P pointertable associated with the selected logical page size. In some examples,the offset may be stored in the remaining bits (e.g., bits 0 to 27 of a4B entry) of the entry in the 512 KB L2P table.

FIG. 4 illustrates an example of an operational flow 400 that supportsdynamic logical page sizes for memory devices in accordance withexamples as disclosed herein. In some examples, operation flow 400 maybe performed by a memory device (such as a memory device 130, 140, or210) in response to receiving a command (e.g., from a host device) towrite a size of data that is smaller than a maximum supported logicalpage size supported by the memory device.

A memory device may include one or more logical pages that support themaximum supported logical page size x (e.g., a 512 KB logical pagesize). For example, the memory device may include a logical page 405that has a logical page size x. In some examples, a host device mayrequest to write an amount of data that is a size less than x. Thememory device may split the logical page 405 into smaller logical pagesin order to accommodate the data. For example, the memory device maysplit the logical page 405 into N logical pages 410 of size y, where yis less than x and is a size of a logical page size supported by thememory device. The memory device may then write the data to one or moreof the logical pages 410. In some cases, the memory device may create alower-level L2P table with entries including the physical addresses ofthe logical pages 410. In some other cases, the memory device may addentries including the physical addresses of the logical pages 410 to anexisting lower-level L2P table associated with logical pages of size y.

The logical page 405 may be associated with an L2P table containingentries that point to logical pages of size x. For example, an entry ofthe L2P table may include the physical address of the logical page 405.After splitting the logical page 405, the memory device may update theentry of the L2P table to indicate that the logical page 405 has beensplit into the logical pages 410. Additionally, the memory device mayupdate the entry to indicate an offset within a lower-level L2P tableassociated with the logical pages 410 where the data is located. Forexample, the memory device may store a value in the MSB that indicatesthat the 512 KB logical page has been split, and three additional bits(e.g., bits 28, 29, 30 of a 4B entry) that may point to an entry of anL2P pointer table associated with the selected logical page size. It isto be understood that this any other specific numeric example providedherein is for the sake of illustrative clarity only and is not limiting,of the claims or otherwise. In some examples, the offset may be storedin the remaining bits of the entry associated with the logical page 405.In some examples, if the MSB is 0, the controller may determine that thelogical page 405 has not been split, and if the MSB is 1, the controllermay determine that the 512 KB logical page has been split. In some otherexamples, the opposite may be true.

In an example, the three additional bits may be used to point to anentry of the L2P pointer table according to the following (given thatthe MSB indicates that the 512 KB logical page has been split). If thethree additional bits in the entry are 000, then the logical page hasbeen split into two 256 KB pages, and some or all of the remaining bitsof the entry may denote the offset in 256 KB addresses. If the threeadditional bits in the entry are 001, then the logical page has beensplit into 4 128 KB pages, and the remaining bits of the entry denotethe offset in 128 KB addresses. If the three additional bits in theentry are 010, then the logical page has been split into 8 64 KB pages,and the remaining bits of the entry denote the offset in 64 KBaddresses. If the three additional bits in the entry are 011, then thelogical page has been split into 16 32 KB pages, and the remaining bitsof the entry denote the offset in 32 KB addresses. If the threeadditional bits in the entry are 100, then the logical page has beensplit into 32 16 KB pages, and the remaining bits of the entry denotethe offset in 16 KB addresses. If the three additional bits in the entryare 101, then the logical page has been split into 64 8 KB pages, andthe remaining bits of the entry denote the offset in 8 KB addresses. Ifthe three additional bits in the entry are 110, then the logical pagehas been split into 128 4 KB pages, and the remaining bits of the entrydenote the offset in 4 KB addresses. Thus, when a memory device splits alogical page 405, an entry of an L2P table that points to the logicalpage 405 may be updated to indicate the location of the smaller logicalpages. Other examples and combinations of the three additional bits maybe possible to denote different logical page splits, and the exampleprovided above should not be considered limiting in scope.

FIG. 5 illustrates an example of a process flow 500 that supportsdynamic logical page sizes for memory devices in accordance withexamples as disclosed herein. Process flow 500 may be performed bycomponents of a memory system, such as memory system 110 described withreference to FIG. 1 . For example, process flow 500 may be performed bya controller and a memory device such as memory system controller 115,controller 205, and memory device 130, 140, 210, as described withreference to FIGS. 1 and 2 , respectively. Process flow 500 may depict aprocess for using L2P tables (such as the L2P tables depicted in FIG. 2and described with reference to FIG. 3 ) to locate data in a memorydevice in response to receiving a read command from a host device. Forclarity, process flow 500 uses the specific example of a memory devicethat has a 512 KB maximum logical page size, but similar processes applyto memory devices that have a different maximum logical page size, whichare also covered under the scope of the disclosure.

At 505, the controller may receive a read command from a host device.The read command may include an LBA of data to be read from the memorydevice.

At 510, the controller may use the LBA as an index to read an entry in amain L2P table (e.g., entry 225-a in main L2P table 215) associated withthe LBA. The main L2P table may be stored in SRAM of the memory device,for example. The entry may include a physical address that points to a512 KB L2P table (e.g., L2P table 220).

The 512 KB L2P table may include entries that either (1) point directlyto a 512 KB logical page (if the 512 KB logical page has not been splitinto smaller logical pages), or (2) include an indication that the 512KB has been split into smaller logical page sizes, along with an offsetvalue that may subsequently be used to locate the data in the smallerlogical page. The 512 KB L2P table and corresponding 512 KB logicalpages may be stored in NAND memory of the memory device, for example.

At 515, the controller may add an offset to the physical addressretrieved from the main L2P table to determine a physical address of aparticular entry in the 512 KB L2P table based on the LBA.

At 520, the controller may read an entry in the 512 KB L2P table locatedat the physical address generated at 515. As previously described, theentry may include either (1) a physical address that points directly toa 512 KB logical page containing the data (if the 512 KB logical pagehas not been split into smaller logical pages), or (2) an indicationthat the 512 KB has been split into smaller logical page sizes forstoring the data, along with an offset value that may be used to locatethe data within the smaller logical pages.

At 525, the controller may determine whether the 512 KB page has beensplit into smaller logical pages based on the entry read at 520. In theexample shown in FIG. 5 , the controller may determine whether the 512KB page has been split based on the value in the MSB of the entry. Ifthe MSB is 0, then the controller may determine that the 512 KB logicalpage has not been split into smaller logical pages. If the MSB is 1,then the controller may determine that the 512 KB logical page has beensplit into smaller logical pages. Other bits in the entry may be used toindicate whether a large logical page has been split into smallerlogical pages without departing from the scope of the disclosure.

If the controller determines at 525 that the 512 KB logical page has notbeen split, then at 530, the controller may add an offset to thephysical address retrieved at 520 to determine a physical address of thestart of the requested data (if the requested data is not located at thestarting physical address for the 512 KB logical page).

At 535, the controller may then read the requested data starting at thephysical address determined at 530 and transmit the data to the hostdevice.

If the controller determines at 525 that the 512 KB logical page hasbeen split, then the controller may perform 540 through 560, as follows.

At 540, the controller may use a portion of the entry retrieved at 520to identify an entry in an L2P pointer table that points to alower-level L2P table associated with the location of the data. In theexample shown in FIG. 5 , the controller may use bits 28, 29, and 30 ofthe entry to find the relevant entry in the L2P pointer table and mayretrieve this entry from the L2P pointer table. In this manner, bits 28,29, and 30 may be used to indicate the logical page size to which thedata was previously written, because each entry in the L2P pointer tablemay be associated with an L2P table for a particular logical page size.

The entry in the L2P pointer table may include a physical address of therelevant lower-level L2P table (e.g., the lower-level L2P tableassociated with the logical page size within which the data is stored)and a length of the lower-level L2P table.

At 545, the controller may add an offset to the physical addressretrieved from the L2P pointer table to generate the physical address ofa specific entry of the lower-level L2P table. In some examples, theremaining bits of the entry retrieved at 520 (e.g., bits 0 to 27) mayindicate the value of the offset, and the controller may calculate theoffset to add to the physical address based on reading the remainingbits.

At 550, the controller may read the entry of the lower-level L2P tablelocated at the physical address generated at 545, and may retrieve thephysical address of the smaller logical page that contains the requesteddata.

If the requested data is not located at the beginning of the smallerlogical page, at 555, the controller may add an offset to the physicaladdress retrieved at 550 to determine a physical address of the locationof the data within the smaller logical page.

At 560, the controller may read the data starting from a location withinthe smaller logical page pointed to by the physical address generated at555, and may then transmit the data to the host device.

FIG. 6 shows a block diagram 600 of a memory system 605 that supportsdynamic logical page sizes for memory devices in accordance withexamples as disclosed herein. The memory system 605 may be an example ofaspects of a memory system as described with reference to FIGS. 1through 5 . The memory system 605 may include a communication component610, an L2P table manager 615, a size component 620, a write component625, a physical address component 630, a read component 635, a pointertable component 640, and an offset component 645. Each of these modulesmay communicate, directly or indirectly, with one another (e.g., via oneor more buses).

In some example, the communication component 610 may receive a writecommand for writing a first amount of data to a memory device, the writecommand associated with a logical address. In some cases, thecommunication component 610 may receive a second write command forwriting a second amount of data to the memory device, the second writecommand including a second logical address.

In some examples, the communication component 610 may receive a readcommand associated with a first logical address that is associated witha starting location of data stored in a memory device. In some cases,the communication component 610 may transmit the data to a host devicefor the memory device.

With reference to the communication component 610 receiving the writecommand, the L2P table manager 615 may read, based on the logicaladdress, a first entry of a first L2P table, where the first L2P tableis for mapping a set of logical addresses to physical addresses of acorresponding first set of logical pages of the memory device that eachhave a first logical page size, and where the first entry of the firstL2P table includes a first physical address of a first logical page ofthe first set of logical pages.

In some examples, the L2P table manager 615 may read, based on thelogical address, a first entry of a main L2P table for mapping a set oflogical addresses to a corresponding set of L2P tables including thefirst L2P table, the first entry of the main L2P table including a thirdphysical address that points to the first L2P table, where reading thefirst entry of the first L2P table includes reading the first entry ofthe first L2P table based on the third physical address.

With reference to the communication component 610 receiving the secondwrite command, in some examples, the L2P table manager 615 may read,based on the second logical address, a second entry of a third L2P tablefor mapping a third set of logical addresses to physical addresses of acorresponding third set of logical pages of the memory device that eachhave the first logical page size, the second entry of the third L2Ptable including a fifth physical address of a third logical page of thethird set of logical pages.

In some examples, the L2P table manager 615 may read, based on thesecond logical address, a second entry of a third L2P table for mappinga third set of logical addresses to physical addresses of acorresponding third set of logical pages of the memory device that eachhave the first logical page size, the second entry of the third L2Ptable including a fifth physical address of a third logical page of thethird set of logical pages.

With reference to the communication component 610 receiving the readcommand, the L2P table manager 615 may read a first entry of a first L2Ptable based on the logical address, where the first entry includes afirst physical address of a first logical page of the memory devicehaving a first logical page size, and where a value of a first portionof the first physical address indicates a second logical page size of asecond logical page of memory that contains the data, the first logicalpage including the second logical page.

In some examples, the L2P table manager 615 may read, based onidentifying a value of a second portion of the first physical address, afirst entry of the L2P pointer table, the first entry of the L2P pointertable including a third physical address.

In some examples, the L2P table manager 615 may read a third entry of amain L2P table based on the logical address, where the third entryincludes a third physical address that points to the first L2P table.

With reference to the communication component 610 receiving the writecommand, the size component 620 may identify, based on a size of thefirst amount of data, a second logical page size. In some examples, thesize component 620 may select the second logical page size from the setof supported logical page sizes.

With reference to the communication component 610 receiving the secondwrite command, in some examples, the size component 620 may identify,based on a second size of the second amount of data, a third logicalpage size. In some cases, the size component 620 may identify that thesecond amount of data corresponds to the first logical page size.

With reference to the communication component 610 receiving the readcommand, the size component 620 may determine, based on the value of thefirst portion of the first physical address, whether the second logicalpage size is different than the first logical page size.

The write component 625 may write, based on the first physical address,at least a portion of the first amount of data to a second logical pageof the memory device having the second logical page size, the firstlogical page including the second logical page. In some examples, thewrite component 625 may write at least a portion of the second amount ofdata to a fourth logical page of the memory device having the thirdlogical page size, where the third logical page includes the fourthlogical page. In some cases, the write component 625 may write thesecond amount of data to the third logical page.

In some examples, the L2P table manager 615 may store, based on the sizecomponent 620 identifying the second logical page size, a first entry ofa second L2P table for mapping a second set of logical addresses tophysical addresses of a corresponding second set of logical pages of thememory device, each logical page of the second set of logical pageshaving the second logical page size, where the first entry in the secondL2P table includes a second physical address of the second logical page.

With reference to the communication component 610 receiving the readcommand, the physical address component 630 may determine, based on thedetermination of whether the second logical page size is different thanthe first logical page size, a second physical address that points tothe starting location of the data within the second logical page.

In some examples, the physical address component 630 may identify avalue of a second portion of the first physical address, where the valueof the second portion of the first physical address points to a firstentry of an L2P pointer table.

The read component 635 may read the data from the starting location ofthe data within the second logical page based on determining the secondphysical address. In some examples, the read component 635 may readbased on identifying the value of the second portion of the firstphysical address, a first entry of the L2P pointer table, the firstentry of the L2P pointer table comprising a third physical address. Insome examples, the read component 635 may read a first portion of datafrom the second logical page. In some cases, the read component 635 mayread a second portion of the data from a third logical page having thesame logical page size as the second logical page.

With reference to the communication component 610 receiving the writecommand, the pointer table component 640 may store, based on identifyingthe second logical page size, a first entry in an L2P pointer table, thefirst entry in the L2P pointer table including a fourth physical addressand a length of the second L2P table, where the fourth physical addresspoints to the second L2P table.

In some examples, the pointer table component 640 may determine that twoor more logical pages having the second logical page size and pointed toby the second L2P table have been deleted. In some cases, the pointertable component 640 may update, based on the determination that the twoor more logical pages have been deleted, the length of the second L2Ptable in the L2P pointer table and the length of the first L2P table inthe first L2P pointer table.

With reference to the communication component 610 receiving the readcommand, the offset component 645 may add an offset to the thirdphysical address to determine a fourth physical address associated witha second entry in a second L2P table, where the offset is indicated by athird portion of the first physical address. In some examples, the readcomponent 635 may read the second entry of the second L2P table, wherethe second entry of the second L2P table includes at least a portion ofthe second physical address.

In some examples, the offset component 645 may add a second offset tothe second entry of the second L2P table to generate the second physicaladdress.

In some examples, the offset component 645 may add an offset to thefirst physical address to determine the second physical address.

With reference to the communication component 610 receiving the readcommand, in some examples, the read component 635 may read a third entryof a main L2P table based on the logical address, where the third entrycomprises a third physical address that points to the first L2P table.In some cases, the offset component 645 may add a third offset to thethird physical address to generate a fourth physical address that pointsto the first entry of the first L2P table, where reading the first entryof the first L2P table includes reading the first entry of the first L2Ptable based on the fourth physical address.

FIG. 7 shows a flowchart illustrating a method or methods 700 thatsupports dynamic logical page sizes for memory devices in accordancewith aspects of the present disclosure. The operations of method 700 maybe implemented by a memory system or its components as described herein.For example, the operations of method 700 may be performed by a memorysystem as described with reference to FIG. 6 . In some examples, amemory system may execute a set of instructions to control thefunctional elements of the memory system to perform the describedfunctions. Additionally or alternatively, a memory system may performaspects of the described functions using special-purpose hardware.

At 705, the memory system may receive a write command for writing afirst amount of data to a memory device, the write command associatedwith a logical address. The operations of 705 may be performed accordingto the methods described herein. In some examples, aspects of theoperations of 705 may be performed by a communication component asdescribed with reference to FIG. 6 .

In some examples, the memory system may store virtual block informationassociated with the memory device and may assign a physical address ofthe data to be written based on the virtual block information. Forexample, the memory system may track which virtual blocks of the memorydevice are free, assign a physical address to the data based on whichvirtual blocks are free, and write the data to the assigned physicaladdress of the memory device. In some examples, the memory system maycreate a mapping between the LBA assigned to the data and the physicaladdress of the data stored in the memory device and may store themapping in a change log stored in the memory system. The memory systemmay subsequently use the mapping stored in the change log to read thedata. In some cases, the memory system may determine to erase themappings stored in the change log (e.g., due to change log sizerestrictions, entering a low power mode). To avoid losing the mappings,the memory system may determine to store the mappings in one or more L2Ptables stored in the memory device. In some cases, 710 to 725 may beimplemented in response to the memory system determining to store themappings in the one or more L2P tables. In some other cases, 710 to 725may be implemented in response to receiving the write command from thehost device at 705.

At 710, the memory system may read, based on the logical address, afirst entry of a first L2P table, where the first L2P table is formapping a set of logical addresses to physical addresses of acorresponding first set of logical pages of the memory device that eachhave a first logical page size, and where the first entry of the firstL2P table includes a first physical address of a first logical page ofthe first set of logical pages. The operations of 710 may be performedaccording to the methods described herein. In some examples, aspects ofthe operations of 710 may be performed by a L2P table manager asdescribed with reference to FIG. 6 .

At 715, the memory system may identify, based on a size of the firstamount of data, a second logical page size. The operations of 715 may beperformed according to the methods described herein. In some examples,aspects of the operations of 715 may be performed by a size component asdescribed with reference to FIG. 6 .

At 720, the memory system may write, based on the first physicaladdress, at least a portion of the first amount of data to a secondlogical page of the memory device having the second logical page size,the first logical page including the second logical page. The operationsof 720 may be performed according to the methods described herein. Insome examples, aspects of the operations of 720 may be performed by awrite component as described with reference to FIG. 6 .

At 725, the memory system may store, based on identifying the secondlogical page size, a first entry of a second L2P table for mapping asecond set of logical addresses to physical addresses of a correspondingsecond set of logical pages of the memory device, each logical page ofthe second set of logical pages having the second logical page size,where the first entry in the second L2P table includes a second physicaladdress of the second logical page. The operations of 725 may beperformed according to the methods described herein. In some examples,aspects of the operations of 725 may be performed by a L2P table manageras described with reference to FIG. 6 .

In some examples, an apparatus as described herein may perform a methodor methods, such as the method 700. The apparatus may include features,means, or instructions (e.g., a non-transitory computer-readable mediumstoring instructions executable by a processor) for receiving a writecommand for writing a first amount of data to a memory device, the writecommand associated with a logical address, reading, based on the logicaladdress, a first entry of a first L2P table, where the first L2P tableis for mapping a set of logical addresses to physical addresses of acorresponding first set of logical pages of the memory device that eachhave a first logical page size, and where the first entry of the firstL2P table includes a first physical address of a first logical page ofthe first set of logical pages, identifying, based on a size of thefirst amount of data, a second logical page size, writing, based on thefirst physical address, at least a portion of the first amount of datato a second logical page of the memory device having the second logicalpage size, the first logical page including the second logical page, andstoring, based on identifying the second logical page size, a firstentry of a second L2P table for mapping a second set of logicaladdresses to physical addresses of a corresponding second set of logicalpages of the memory device, each logical page of the second set oflogical pages having the second logical page size, where the first entryin the second L2P table includes a second physical address of the secondlogical page.

Some examples of the method 700 and the apparatus described herein mayfurther include operations, features, means, or instructions forreading, based on the logical address, a first entry of a main L2P tablefor mapping a set of logical addresses to a corresponding set of L2Ptables including the first L2P table, the first entry of the main L2Ptable including a third physical address that points to the first L2Ptable, where reading the first entry of the first L2P table includesreading the first entry of the first L2P table based on the thirdphysical address.

In some cases of the method 700 and the apparatus described herein, themain L2P table may be stored in a first type of memory, and the firstL2P table may be stored in a second type of memory.

Some examples of the method 700 and the apparatus described herein mayfurther include operations, features, means, or instructions forstoring, based on identifying the second logical page size, a firstentry in an L2P pointer table, the first entry in the L2P pointer tableincluding a fourth physical address and a length of the second L2Ptable, where the fourth physical address points to the second L2P table.

Some examples of the method 700 and the apparatus described herein mayfurther include operations, features, means, or instructions forreceiving a second write command for writing a second amount of data tothe memory device, the second write command including a second logicaladdress, reading, based on the second logical address, a second entry ofa third L2P table for mapping a third set of logical addresses tophysical addresses of a corresponding third set of logical pages of thememory device that each may have the first logical page size, the secondentry of the third L2P table including a fifth physical address of athird logical page of the third set of logical pages, identifying, basedon a second size of the second amount of data, a third logical pagesize, and writing at least a portion of the second amount of data to afourth logical page of the memory device having the third logical pagesize, where the third logical page includes the fourth logical page.

In some cases of the method 700 and the apparatus described herein, thethird logical page size may be a different size than the second logicalpage size, and the method 700 and the apparatus described herein mayfurther include operations, features, means, or instructions forstoring, based on identifying the third logical page size, a secondentry in the L2P pointer table, the second entry in the L2P pointertable including a sixth physical address and a length of a fourth L2Ptable, where the sixth physical address points to the fourth L2P tableassociated with the fourth logical page.

In some implementations of the method 700 and the apparatus describedherein, the third logical page size may be the same size as the secondlogical page size, and the method 700 and the apparatus described hereinmay further include operations, features, means, or instructions forupdating the length of the second L2P table in the first entry of theL2P pointer table based on the third logical page size being the samesize as the second logical page size.

In some examples of the method 700 and the apparatus described herein,the first L2P table and the third L2P table may be the same L2P table.

In some cases of the method 700 and the apparatus described herein, thefirst L2P table and the third L2P table may be different L2P tables.

Some examples of the method 700 and the apparatus described herein mayfurther include operations, features, means, or instructions fordetermining that two or more logical pages having the second logicalpage size and pointed to by the second L2P table may have been deleted,and updating, based on the determination that the two or more logicalpages may have been deleted, the length of the second L2P table in theL2P pointer table and the length of the first L2P table in the first L2Ppointer table.

Some examples of the method 700 and the apparatus described herein mayfurther include operations, features, means, or instructions forreceiving a second write command for writing a second amount of data tothe memory device, the second write command including a second logicaladdress, reading, based on the second logical address, a second entry ofa third L2P table for mapping a third set of logical addresses tophysical addresses of a corresponding third set of logical pages of thememory device that each may have the first logical page size, the secondentry of the third L2P table including a fifth physical address of athird logical page of the third set of logical pages, identifying thatthe second amount of data corresponds to the first logical page size,and writing the second amount of data to the third logical page.

In some examples of the method 700 and the apparatus described herein,the first logical page size may be a maximum logical page size of a setof supported logical page sizes associated with the memory device, theset of supported logical page sizes including the second logical pagesize.

In some examples of the method 700 and the apparatus described herein,identifying the second logical page size may include operations,features, means, or instructions for selecting the second logical pagesize from the set of supported logical page sizes.

FIG. 8 shows a flowchart illustrating a method or methods 800 thatsupports dynamic logical page sizes for memory devices in accordancewith aspects of the present disclosure. The operations of method 800 maybe implemented by a memory system or its components as described herein.For example, the operations of method 800 may be performed by a memorysystem as described with reference to FIG. 6 . In some examples, amemory system may execute a set of instructions to control thefunctional elements of the memory system to perform the describedfunctions. Additionally or alternatively, a memory system may performaspects of the described functions using special-purpose hardware.

At 805, the memory system may receive a read command associated with afirst logical address that is associated with a starting location ofdata stored in a memory device. The operations of 805 may be performedaccording to the methods described herein. In some examples, aspects ofthe operations of 805 may be performed by a communication component asdescribed with reference to FIG. 6 .

At 810, the memory system may read a first entry of a first L2P tablebased on the logical address, where the first entry includes a firstphysical address of a first logical page of the memory device having afirst logical page size, and where a value of a first portion of thefirst physical address indicates a second logical page size of a secondlogical page of memory that contains the data, the first logical pageincluding the second logical page. The operations of 810 may beperformed according to the methods described herein. In some examples,aspects of the operations of 810 may be performed by a L2P table manageras described with reference to FIG. 6 .

At 815, the memory system may determine, based on the value of the firstportion of the first physical address, whether the second logical pagesize is different than the first logical page size. The operations of815 may be performed according to the methods described herein. In someexamples, aspects of the operations of 815 may be performed by a sizecomponent as described with reference to FIG. 6 .

At 820, the memory system may determine, based on the determination ofwhether the second logical page size is different than the first logicalpage size, a second physical address that points to the startinglocation of the data within the second logical page. The operations of820 may be performed according to the methods described herein. In someexamples, aspects of the operations of 820 may be performed by aphysical address component as described with reference to FIG. 6 .

At 825, the memory system may read the data from the starting locationof the data within the second logical page based on the second physicaladdress. The operations of 825 may be performed according to the methodsdescribed herein. In some examples, aspects of the operations of 825 maybe performed by a read component as described with reference to FIG. 6 .

At 830, the memory system may transmit the data to a host device for thememory device. The operations of 830 may be performed according to themethods described herein. In some examples, aspects of the operations of830 may be performed by a communication component as described withreference to FIG. 6 .

In some examples, an apparatus as described herein may perform a methodor methods, such as the method 800. The apparatus may include features,means, or instructions (e.g., a non-transitory computer-readable mediumstoring instructions executable by a processor) for receiving a readcommand associated with a first logical address that is associated witha starting location of data stored in a memory device, reading a firstentry of a first L2P table based on the logical address, where the firstentry includes a first physical address of a first logical page of thememory device having a first logical page size, and where a value of afirst portion of the first physical address indicates a second logicalpage size of a second logical page of memory that contains the data, thefirst logical page including the second logical page, determining, basedon the value of the first portion of the first physical address, whetherthe second logical page size is different than the first logical pagesize, determining, based on the determination of whether the secondlogical page size is different than the first logical page size, asecond physical address that points to the starting location of the datawithin the second logical page, reading the data from the startinglocation of the data within the second logical page based on the secondphysical address, and transmitting the data to a host device for thememory device.

In some examples of the method 800 and the apparatus described herein,the second logical page size may be different than the first logicalpage size, and where determining the second physical address may includeoperations, features, means, or instructions for identifying a value ofa second portion of the first physical address, where the value of thesecond portion of the first physical address points to a first entry ofan L2P pointer table, reading, based on identifying the value of thesecond portion of the first physical address, a first entry of the L2Ppointer table, the first entry of the L2P pointer table including athird physical address, adding an offset to the third physical addressto determine a fourth physical address associated with a second entry ina second L2P table, where the offset may be indicated by a third portionof the first physical address, and reading the second entry of thesecond L2P table, where the second entry of the second L2P tableincludes at least a portion of the second physical address.

Some examples of the method 800 and the apparatus described herein mayfurther include operations, features, means, or instructions for addinga second offset to the second entry of the second L2P table to generatethe second physical address.

In some examples of the method 800 and the apparatus described herein,the second logical page size may be the same as the first logical pagesize, and determining the second physical address may includeoperations, features, means, or instructions for adding an offset to thefirst physical address to determine the second physical address.

Some examples of the method 800 and the apparatus described herein mayfurther include operations, features, means, or instructions for readinga third entry of a main L2P table based on the logical address, wherethe third entry includes a third physical address that points to thefirst L2P table, and adding a third offset to the third physical addressto generate a fourth physical address that points to the first entry ofthe first L2P table, where reading the first entry of the first L2Ptable includes reading the first entry of the first L2P table based onthe fourth physical address.

In some examples of the method 800 and the apparatus described herein,reading the data from the starting location of the data within thesecond logical page may include operations, features, means, orinstructions for reading a first portion of data from the second logicalpage, and reading a second portion of the data from a third logical pagehaving the same logical page size as the second logical page.

It should be noted that the methods described herein describe possibleimplementations, and that the operations and the steps may be rearrangedor otherwise modified and that other implementations are possible.Further, portions from two or more of the methods may be combined.

An apparatus is described. The apparatus may include a memory device anda controller for the memory device, the controller configured to causethe apparatus to receive a write command for writing a first amount ofdata to a memory device, the write command associated with a logicaladdress, read, based on the logical address, a first entry of a firstL2P table, where the first L2P table is for mapping a set of logicaladdresses to physical addresses of a corresponding first set of logicalpages of the memory device that each have a first logical page size, andwhere the first entry of the first L2P table includes a first physicaladdress of a first logical page of the first set of logical pages,identify, based on a size of the first amount of data, a second logicalpage size, write, based on the first physical address, at least aportion of the first amount of data to a second logical page of thememory device having the second logical page size, the first logicalpage including the second logical page, and store, based on identifyingthe second logical page size, a first entry of a second L2P table formapping a second set of logical addresses to physical addresses of acorresponding second set of logical pages of the memory device, eachlogical page of the second set of logical pages having the secondlogical page size, where the first entry in the second L2P tableincludes a second physical address of the second logical page.

In some examples, the controller may be further configured to cause theapparatus to read, based on the logical address, a first entry of a mainL2P table for mapping a set of logical addresses to a corresponding setof L2P tables including the first L2P table, the first entry of the mainL2P table including a third physical address that points to the firstL2P table, where reading the first entry of the first L2P table includesreading the first entry of the first L2P table based on the thirdphysical address.

In some cases, the main L2P table may be stored in a first type ofmemory, and the first L2P table may be stored in a second type ofmemory.

In some instances, the controller may be further configured to cause theapparatus to store, based on identifying the second logical page size, afirst entry in an L2P pointer table, the first entry in the L2P pointertable including a fourth physical address and a length of the second L2Ptable, where the fourth physical address points to the second L2P table.

In some examples, the controller may be further configured to cause theapparatus to receive a second write command for writing a second amountof data to the memory device, the second write command including asecond logical address, read, based on the second logical address, asecond entry of a third L2P table for mapping a third set of logicaladdresses to physical addresses of a corresponding third set of logicalpages of the memory device that each may have the first logical pagesize, the second entry of the third L2P table including a fifth physicaladdress of a third logical page of the third set of logical pages,identify, based on a second size of the second amount of data, a thirdlogical page size, and write at least a portion of the second amount ofdata to a fourth logical page of the memory device having the thirdlogical page size, where the third logical page includes the fourthlogical page.

In some cases, the third logical page size is a different size than thesecond logical page size, and the controller may be further configuredto cause the apparatus to store, based on identifying the third logicalpage size, a second entry in the L2P pointer table, the second entry inthe L2P pointer table comprising a sixth physical address and a lengthof a fourth L2P table, where the sixth physical address points to thefourth L2P table associated with the fourth logical page.

In some examples, the third logical page size is the same size as thesecond logical page size, and the controller may be further configuredto cause the apparatus to update the length of the second L2P table inthe first entry of the L2P pointer table based on the third logical pagesize being the same size as the second logical page size

In some cases, the first L2P table and the third L2P table may be thesame L2P table.

In some instances, the first L2P table and the third L2P table may bedifferent L2P tables.

In some examples, the controller may be further configured to cause theapparatus to determine that two or more logical pages having the secondlogical page size and pointed to by the second L2P table may have beendeleted, and update, based on the determination that the two or morelogical pages may have been deleted, the length of the second L2P tablein the L2P pointer table and the length of the first L2P table in thefirst L2P pointer table.

In some cases, the controller may be further configured to cause theapparatus to receive a second write command for writing a second amountof data to the memory device, the second write command including asecond logical address, read, based on the second logical address, asecond entry of a third L2P table for mapping a third set of logicaladdresses to physical addresses of a corresponding third set of logicalpages of the memory device that each may have the first logical pagesize, the second entry of the third L2P table including a fifth physicaladdress of a third logical page of the third set of logical pages,identify that the second amount of data corresponds to the first logicalpage size, and write the second amount of data to the third logicalpage.

In some instances, the first logical page size is a maximum logical pagesize of a set of supported logical page sizes associated with the memorydevice, the set of supported logical page sizes including the secondlogical page size.

In some examples, the controller may be further configured to cause theapparatus to select the second logical page size from the set ofsupported logical page sizes.

An apparatus is described. The apparatus may include a memory device anda controller for the memory device, the controller configured to causethe apparatus to receive a read command associated with a first logicaladdress that is associated with a starting location of data stored in amemory device, read a first entry of a first L2P table based on thelogical address, where the first entry includes a first physical addressof a first logical page of the memory device having a first logical pagesize, and where a value of a first portion of the first physical addressindicates a second logical page size of a second logical page of memorythat contains the data, the first logical page including the secondlogical page, determine, based on the value of the first portion of thefirst physical address, whether the second logical page size isdifferent than the first logical page size, determine, based on thedetermination of whether the second logical page size is different thanthe first logical page size, a second physical address that points tothe starting location of the data within the second logical page, readthe data from the starting location of the data within the secondlogical page based on the second physical address, and transmit the datato a host device for the memory device.

In some examples, the second logical page size may be different than thefirst logical page size, and the controller may be further configured tocause the apparatus to identify a value of a second portion of the firstphysical address, where the value of the second portion of the firstphysical address points to a first entry of an L2P pointer table, read,based on identifying the value of the second portion of the firstphysical address, a first entry of the L2P pointer table, the firstentry of the L2P pointer table including a third physical address, addan offset to the third physical address to determine a fourth physicaladdress associated with a second entry in a second L2P table, where theoffset may be indicated by a third portion of the first physicaladdress, and read the second entry of the second L2P table, where thesecond entry of the second L2P table includes at least a portion of thesecond physical address.

In some cases, the controller may be further configured to cause theapparatus to add a second offset to the second entry of the second L2Ptable to generate the second physical address.

In some examples, the second logical page size may be the same as thefirst logical page size, and, to determine the second physical address,the controller may be further configured to cause the apparatus to addan offset to the first physical address to determine the second physicaladdress.

In some cases, the controller may be further configured to cause theapparatus to read a third entry of a main L2P table based on the logicaladdress, where the third entry includes a third physical address thatpoints to the first L2P table, and add a third offset to the thirdphysical address to generate a fourth physical address that points tothe first entry of the first L2P table, where, to read the first entryof the first L2P table the controller may be further configured to causethe apparatus to read the first entry of the first L2P table based onthe fourth physical address.

In some instances, the controller may be further configured to cause theapparatus to read a first portion of data from the second logical page,and read a second portion of the data from a third logical page havingthe same logical page size as the second logical page.

Information and signals described herein may be represented using any ofa variety of different technologies and techniques. For example, data,instructions, commands, information, signals, bits, symbols, and chipsthat may be referenced throughout the above description may berepresented by voltages, currents, electromagnetic waves, magneticfields or particles, optical fields or particles, or any combinationthereof. Some drawings may illustrate signals as a single signal;however, it will be understood by a person of ordinary skill in the artthat the signal may represent a bus of signals, where the bus may have avariety of bit widths.

The terms “electronic communication,” “conductive contact,” “connected,”and “coupled” may refer to a relationship between components thatsupports the flow of signals between the components. Components areconsidered in electronic communication with (or in conductive contactwith or connected with or coupled with) one another if there is anyconductive path between the components that can, at any time, supportthe flow of signals between the components. At any given time, theconductive path between components that are in electronic communicationwith each other (or in conductive contact with or connected with orcoupled with) may be an open circuit or a closed circuit based on theoperation of the device that includes the connected components. Theconductive path between connected components may be a direct conductivepath between the components or the conductive path between connectedcomponents may be an indirect conductive path that may includeintermediate components, such as switches, transistors, or othercomponents. In some examples, the flow of signals between the connectedcomponents may be interrupted for a time, for example, using one or moreintermediate components such as switches or transistors.

The term “coupling” refers to condition of moving from an open-circuitrelationship between components in which signals are not presentlycapable of being communicated between the components over a conductivepath to a closed-circuit relationship between components in whichsignals are capable of being communicated between components over theconductive path. When a component, such as a controller, couples othercomponents together, the component initiates a change that allowssignals to flow between the other components over a conductive path thatpreviously did not permit signals to flow.

The term “isolated” refers to a relationship between components in whichsignals are not presently capable of flowing between the components.Components are isolated from each other if there is an open circuitbetween them. For example, two components separated by a switch that ispositioned between the components are isolated from each other when theswitch is open. When a controller isolates two components, thecontroller affects a change that prevents signals from flowing betweenthe components using a conductive path that previously permitted signalsto flow.

The devices discussed herein, including a memory array, may be formed ona semiconductor substrate, such as silicon, germanium, silicon-germaniumalloy, gallium arsenide, gallium nitride, etc. In some examples, thesubstrate is a semiconductor wafer. In other examples, the substrate maybe a silicon-on-insulator (SOI) substrate, such as silicon-on-glass(SOG) or silicon-on-sapphire (SOP), or epitaxial layers of semiconductormaterials on another substrate. The conductivity of the substrate, orsub-regions of the substrate, may be controlled through doping usingvarious chemical species including, but not limited to, phosphorous,boron, or arsenic. Doping may be performed during the initial formationor growth of the substrate, by ion-implantation, or by any other dopingmeans.

A switching component or a transistor discussed herein may represent afield-effect transistor (FET) and comprise a three terminal deviceincluding a source, drain, and gate. The terminals may be connected toother electronic elements through conductive materials, e.g., metals.The source and drain may be conductive and may comprise a heavily-doped,e.g., degenerate, semiconductor region. The source and drain may beseparated by a lightly-doped semiconductor region or channel. If thechannel is n-type (i.e., majority carriers are electrons), then the FETmay be referred to as a n-type FET. If the channel is p-type (i.e.,majority carriers are holes), then the FET may be referred to as ap-type FET. The channel may be capped by an insulating gate oxide. Thechannel conductivity may be controlled by applying a voltage to thegate. For example, applying a positive voltage or negative voltage to ann-type FET or a p-type FET, respectively, may result in the channelbecoming conductive. A transistor may be “on” or “activated” when avoltage greater than or equal to the transistor's threshold voltage isapplied to the transistor gate. The transistor may be “off” or“deactivated” when a voltage less than the transistor's thresholdvoltage is applied to the transistor gate.

The description set forth herein, in connection with the appendeddrawings, describes example configurations and does not represent allthe examples that may be implemented or that are within the scope of theclaims. The term “exemplary” used herein means “serving as an example,instance, or illustration,” and not “preferred” or “advantageous overother examples.” The detailed description includes specific details toproviding an understanding of the described techniques. Thesetechniques, however, may be practiced without these specific details. Insome instances, well-known structures and devices are shown in blockdiagram form to avoid obscuring the concepts of the described examples.

In the appended figures, similar components or features may have thesame reference label. Further, various components of the same type maybe distinguished by following the reference label by a dash and a secondlabel that distinguishes among the similar components. If just the firstreference label is used in the specification, the description isapplicable to any one of the similar components having the same firstreference label irrespective of the second reference label.

The functions described herein may be implemented in hardware, softwareexecuted by a processor, firmware, or any combination thereof. Ifimplemented in software executed by a processor, the functions may bestored on or transmitted over as one or more instructions or code on acomputer-readable medium. Other examples and implementations are withinthe scope of the disclosure and appended claims. For example, due to thenature of software, functions described herein can be implemented usingsoftware executed by a processor, hardware, firmware, hardwiring, orcombinations of any of these. Features implementing functions may alsobe physically located at various positions, including being distributedsuch that portions of functions are implemented at different physicallocations.

For example, the various illustrative blocks and modules described inconnection with the disclosure herein may be implemented or performedwith a general-purpose processor, a DSP, an ASIC, an FPGA or otherprogrammable logic device, discrete gate or transistor logic, discretehardware components, or any combination thereof designed to perform thefunctions described herein. A general-purpose processor may be amicroprocessor, but in the alternative, the processor may be anyprocessor, controller, microcontroller, or state machine. A processormay also be implemented as a combination of computing devices (e.g., acombination of a DSP and a microprocessor, multiple microprocessors, oneor more microprocessors in conjunction with a DSP core, or any othersuch configuration).

As used herein, including in the claims, “or” as used in a list of items(for example, a list of items prefaced by a phrase such as “at least oneof” or “one or more of”) indicates an inclusive list such that, forexample, a list of at least one of A, B, or C means A or B or C or AB orAC or BC or ABC (i.e., A and B and C). Also, as used herein, the phrase“based on” shall not be construed as a reference to a closed set ofconditions. For example, an exemplary step that is described as “basedon condition A” may be based on both a condition A and a condition Bwithout departing from the scope of the present disclosure. In otherwords, as used herein, the phrase “based on” shall be construed in thesame manner as the phrase “based at least in part on.”

Computer-readable media includes both non-transitory computer storagemedia and communication media including any medium that facilitatestransfer of a computer program from one place to another. Anon-transitory storage medium may be any available medium that can beaccessed by a general purpose or special purpose computer. By way ofexample, and not limitation, non-transitory computer-readable media cancomprise RAM, ROM, electrically erasable programmable read-only memory(EEPROM), compact disk (CD) ROM or other optical disk storage, magneticdisk storage or other magnetic storage devices, or any othernon-transitory medium that can be used to carry or store desired programcode means in the form of instructions or data structures and that canbe accessed by a general-purpose or special-purpose computer, or ageneral-purpose or special-purpose processor. Also, any connection isproperly termed a computer-readable medium. For example, if the softwareis transmitted from a website, server, or other remote source using acoaxial cable, fiber optic cable, twisted pair, digital subscriber line(DSL), or wireless technologies such as infrared, radio, and microwave,then the coaxial cable, fiber optic cable, twisted pair, digitalsubscriber line (DSL), or wireless technologies such as infrared, radio,and microwave are included in the definition of medium. Disk and disc,as used herein, include CD, laser disc, optical disc, digital versatiledisc (DVD), floppy disk and Blu-ray disc where disks usually reproducedata magnetically, while discs reproduce data optically with lasers.Combinations of the above are also included within the scope ofcomputer-readable media.

The description herein is provided to enable a person skilled in the artto make or use the disclosure. Various modifications to the disclosurewill be apparent to those skilled in the art, and the generic principlesdefined herein may be applied to other variations without departing fromthe scope of the disclosure. Thus, the disclosure is not limited to theexamples and designs described herein, but is to be accorded thebroadest scope consistent with the principles and novel featuresdisclosed herein.

1. (canceled)
 2. An apparatus comprising: a memory device; and acontroller for the memory device and configured to cause the apparatusto: receive a write command for writing data to the memory device, thewrite command associated with a logical address; read, based at least inpart on the logical address, a first entry of a firstlogical-to-physical (L2P) table associated with a first plurality oflogical pages each with a first logical page size, the first entry ofthe first L2P table corresponding to a first logical page of the firstplurality of logical pages; write, based at least in part on reading thefirst entry, at least a portion of the data to a second logical page ofthe memory device having a second logical page size, the first logicalpage comprising the second logical page; and add, based at least in parton writing at least the portion of the data to the second logical page,a first entry to a second L2P table associated with a second pluralityof logical pages each with the second logical page size, the first entryof the second L2P table corresponding to the second logical page.
 3. Theapparatus of claim 2, wherein the controller is further configured tocause the apparatus to: read, based at least in part on the logicaladdress, a first entry of a main L2P table associated with a pluralityof L2P tables comprising the first L2P table, the first entry of themain L2P table indicating a mapping between the logical address and thefirst L2P table, wherein reading the first entry of the first L2P tableis based at least in part on the mapping between the logical address andthe first L2P table.
 4. The apparatus of claim 2, wherein the controlleris further configured to cause the apparatus to: identify, based atleast in part on a size of the data, the second logical page size; andadd, based at least in part on identifying the second logical page size,a first entry to an L2P pointer table, the first entry in the L2Ppointer table comprising a location and a length of the second L2Ptable.
 5. The apparatus of claim 4, wherein the controller is furtherconfigured to cause the apparatus to: receive a second write command forwriting second data to the memory device, the second write commandassociated with a second logical address; read, based at least in parton the second logical address, a second entry of a third L2P tableassociated with a third plurality of logical pages each with the firstlogical page size, the second entry of the third L2P table correspondingto a third logical page of the third plurality of logical pages; andwrite, based at least in part on reading the second entry, at least aportion of the second data to a fourth logical page of the memory devicehaving a third logical page size, the third logical page comprising thefourth logical page.
 6. The apparatus of claim 5, wherein the thirdlogical page size is a different size than the second logical page size,the controller further configured to cause the apparatus to: identify,based at least in part on a second size of the second data, the thirdlogical page size; and add, based at least in part on identifying thethird logical page size, a second entry to the L2P pointer table, thesecond entry comprising a length of a fourth L2P table associated withthe fourth logical page.
 7. The apparatus of claim 5, wherein the thirdlogical page size is a same size as the second logical page size, thecontroller further configured to cause the apparatus to: store a newlength of the second L2P table in the first entry of the L2P pointertable based at least in part on the third logical page size being thesame size as the second logical page size.
 8. The apparatus of claim 5,wherein the first L2P table and the third L2P table are a same L2P tableor are different L2P tables.
 9. The apparatus of claim 4, wherein thecontroller is further configured to cause the apparatus to: delete twoor more logical pages having the second logical page size and indicatedby the second L2P table; and store, based at least in part on deletingthe two or more logical pages, a new length of the second L2P table inthe L2P pointer table.
 10. The apparatus of claim 4, wherein thecontroller is further configured to cause the apparatus to: determinethat two or more logical pages having the second logical page size andindicated by the second L2P table include invalid data; and merge, basedat least in part on the determination that the two or more logical pagesinclude invalid data, the two or more logical pages into a fifth logicalpage having a fifth logical page size greater the second logical pagesize.
 11. The apparatus of claim 10, wherein the controller is furtherconfigured to cause the apparatus to: remove, based at least in part onthe merging, two or more entries from the second L2P table correspondingto the two or more logical pages; and shift one or more remainingentries of the second L2P table to occupy one or more gaps of the secondL2P table associated with removing the two or more entries, wherein theone or more remaining entries comprise continuous entries based at leastin part on the shifting.
 12. The apparatus of claim 11, wherein thecontroller is further configured to cause the apparatus to: store a newlength of the second L2P table in the first entry of the L2P pointertable in accordance with removing the two or more entries from thesecond L2P table.
 13. The apparatus of claim 2, wherein the controlleris further configured to cause the apparatus to: receive a second writecommand for writing second data to the memory device, the second writecommand comprising a second logical address; read, based at least inpart on the second logical address, a second entry of a third L2P tableassociated with a third plurality of logical pages each with the firstlogical page size, the second entry of the third L2P table correspondingto a third logical page of the third plurality of logical pages; andwrite the second data to the third logical page.
 14. The apparatus ofclaim 2, wherein the first logical page size is a maximum logical pagesize of a plurality of supported logical page sizes associated with thememory device, the plurality of supported logical page sizes comprisingthe second logical page size.
 15. An apparatus comprising: a memorydevice; and a controller for the memory device and configured to causethe apparatus to: receive a read command to read data from the memorydevice, the read command associated with a first logical address; read afirst entry of a first logical-to-physical (L2P) table based at least inpart on the first logical address, wherein the first entry comprises afirst location associated with a first logical page of the memory devicehaving a first logical page size, the first logical page comprising asecond logical page having a second logical page size; read, based atleast in part on the second logical page size being different than thefirst logical page size, the data from the second logical page based atleast in part on a second location associated with the second logicalpage; and transmit the data to a host system for the memory device. 16.The apparatus of claim 15, wherein the second logical page size isdifferent than the first logical page size, and wherein, to determine asecond location of the second logical page, the controller configured tocause the apparatus to: identify a value of the first location of thefirst logical page, wherein the value indicates a first entry of an L2Ppointer table; read, based at least in part on identifying the value ofthe first location, a first entry of the L2P pointer table, the firstentry of the L2P pointer table comprising a third location associatedwith a third logical page; determine a fourth location associated with asecond entry in a second L2P table based at least in part on the thirdlocation and an offset, wherein the offset is indicated by a secondvalue associated with the first location; and read the second entry ofthe second L2P table based at least in part on determining the fourthlocation.
 17. The apparatus of claim 16, wherein the controller isfurther configured to cause the apparatus to: determine the secondlocation based at least in part on the second entry of the second L2Ptable and a second offset.
 18. The apparatus of claim 15, wherein thesecond logical page size is the same as the first logical page size, andwherein, to determine the second location, the controller is furtherconfigured to cause the apparatus to: determine the second locationbased at least in part on the first location and an offset.
 19. Theapparatus of claim 15, wherein the controller is further configured tocause the apparatus to: read a third entry of a main L2P table based atleast in part on the first logical address, wherein the third entrycomprises a third location indicating the first L2P table; and determinea fourth location based at least in part on the third location and anoffset, the fourth location indicating the first entry of the first L2Ptable, wherein reading the first entry of the first L2P table areexecutable by the controller to cause the apparatus to read the firstentry of the first L2P table based at least in part on the fourthlocation.
 20. The apparatus of claim 15, wherein, to read the data fromthe second logical page, the controller is further configured to causethe apparatus to: read a first portion of data from the second logicalpage; and read a second portion of the data from a third logical pagehaving a same logical page size as the second logical page.
 21. Anon-transitory computer-readable medium storing code comprisinginstructions which, when executed by a processor of an electronicdevice, cause the electronic device to: receive a write command forwriting data to a memory device, the write command associated with alogical address; read, based at least in part on the logical address, afirst entry of a first logical-to-physical (L2P) table associated with afirst plurality of logical pages each with a first logical page size,the first entry of the first L2P table corresponding to a first logicalpage of the first plurality of logical pages; write, based at least inpart on reading the first entry, at least a portion of the data to asecond logical page of the memory device having a second logical pagesize, the first logical page comprising the second logical page; andadd, based at least in part on writing at least the portion of the datato the second logical page, a first entry to a second L2P tableassociated with a second plurality of logical pages each with the secondlogical page size, the first entry of the second L2P table correspondingto the second logical page.